This invention relates in general to the foundry arts and metallurgy. It is widely known to form articles from metal. One such operation is casting; another is pressure molding. In either operation a metal is chosen from which a final article is to be formed. Next, the metal is heated until it melts into a molten, or liquid, state. Typically, the ingots are melted in a main furnace in a foundry, or metal shop.
A die or mold, in the negative shape of the final article, is provided. The molten metal is then poured, with gravity casting, or injected, with pressure casting, into the die or mold. In gravity casting, the molten metal is allowed to cure, or harden, in the die without additional pressure. In pressure molding, the molten metal is forced into the mold under pressure and/or cured under pressure. The final article is then removed from the die or mold and may or may not be machined. During machining, the article may have extraneous material removed by cutting or any other suitable operation, the surface of the article may be polished to a finished surface, or the article may undergo any other suitable machining operation.
Often a second, or charge, furnace is utilized in the process. The charge furnace receives molten metal from the main furnace and maintains the molten state and/or prepares the molten metal for placement into the die or mold. The charge furnace is typically located near the die or mold. In a large foundry operation with many dies or molds, the foundry may have several charge furnaces, each associated with one die or mold.
Referring to the drawings, there is illustrated in FIGS. 1 and 2 a known arrangement for delivery of molten metal from a main furnace to a charge furnace. As illustrated in FIG. 1, a container, or ladle, 10 is mounted upon a forklift truck 12. The container 10 includes a generally cylindrical main body 14 with a closed bottom 16 and an open top 18. Typically, the container 10 is formed from tempered steel. The container 10 also includes a pair of support ribs 20. The ribs 20 are formed longitudinally, i.e. parallel to the centrally axis of the main body 14, along opposite portions of the main body 14 and extend in a radial direction therefrom. As shown, the ribs 20 are disposed 180 degrees from each other about the circumference of the main body 14. Each rib 20 has at least one tine receiving aperture 22 formed therethrough.
As also illustrated by FIGS. 1 and 2, the forklift truck 12 has a pair of tines 24. The tines are connected to a rotary device (not shown) mounted upon the forklift truck 12 and operable to rotate the tines relative to the truck. The container 10 is transported by the forklift truck 12 by first inserting the tines 24 through the rib apertures 22 and then lifting the container 10.
The container 10 is charged with molten metal 26 from a central furnace 28 by first maneuvering the container 10 below the end of a furnace chute 30. The molten metal is then gravity discharged through the chute 30 from the furnace 28 and into the container 10. The container 10 and the molten metal 26 is then be moved by the forklift truck 12 to a charge furnace 32, which is shown in FIG. 2. At the charge furnace 32, a cover (not shown) over a charging port 33 is opened and one end of a portable transfer chute 34 is inserted into the charging port 33. The forklift truck 12 is then maneuvered to place the container 10 adjacent to the other end of the transfer chute 34. In addition to placement of the forklift truck 12 relative to the transfer chute 34 and the charge furnace 32, the container 10 is usually adjusted in an upward or downward vertical direction, as indicated by the double headed arrow labeled A. As shown in FIG. 2, the container 10 is then rotated relative to the forklift truck 12 by the forklift truck rotary device, as indicated by the arrow labeled B. The molten metal 26 in the container 10 is then discharged under the force of gravity from the container 10 and down the chute 34 into the charge furnace 32. A spout (not shown) is typically formed in the top edge of the container 10 to direct the flow of the molten metal from the container and into the end of the transfer chute 34. The container 10 is then rotated back to its original position relative to the forklift truck and the forklift truck 12 is moved away from the end of the transfer chute 34, allowing removal of the chute and closure of the cover over the furnace charging port.
The maneuvering required to position the container relative to a charge furnace causes a significant amount of turbulence and oxidation in the molten metal 26 during transfer of the molten metal into the charge furnace, thus creating undesired impurities in the final article. Accordingly, it would be desirable to provide an apparatus for the delivery of molten metal that reduces the disturbance of the molten metal.